Abstract

Organometallic vapor phase epitaxy has achieved remarkable recent success, becoming the most promising technique for the ultimate production of III/V materials and device structures. Unfortunately, our understanding of the growth process remains primitive. In this letter we report a new technique for tracing the reactions by conducting the epitaxialgrowth in a D2 ambient using a time‐of‐flight mass spectrometer to analyze the product molecules. The pyrolysisreactions were studied for PH3, both alone and in the presence of trimethylindium (TMIn), and for TMIn alone and in the presence of PH3. For the reactants alone, the PH3pyrolysis is completely heterogeneous at the InP surface, while TMIn pyrolyzes mostly homogeneously in the gas phase. For TMIn and PH3 together, the reaction mechanism is entirely different, and the pyrolysis temperatures for both PH3 and TMIn are lowered. Since the reaction produces only CH4 molecules, with a complete absence of CH3D at high ratios of PH3 to TMIn, we hypothesize that InPgrowth is initiated by the direct interaction of TMIn and PH3 in the vapor phase.